Method and apparatus

ABSTRACT

A method comprises determining in a base station of a first cell of a first network that there is an inactive second cell of a second, different network which is a candidate cell for a user equipment and causing an activation message to be sent to cause the activation of said inactive second cell.

Some embodiments relate to a method and apparatus and in particular butnot exclusively to a method and apparatus which for example permits thesharing of resources between operators.

A communication system can be seen as a facility that enablescommunication sessions between two or more nodes such as fixed or mobilecommunication devices, access points such as base stations, servers,machine type servers, routers, and so on. A communication system andcompatible communicating devices typically operate in accordance with agiven standard or specification which sets out what the various entitiesassociated with the system are permitted to do and how that should beachieved. For example, the standards, specifications and relatedprotocols can define the manner how communication devices shallcommunicate with the access points, how various aspects of thecommunications shall be implemented and how the devices andfunctionalities thereof shall be configured.

A user can access the communication system by means of an appropriatecommunication device. A communication device of a user is often referredto as user equipment (UE) or terminal.

Signals can be carried on wired or wireless carriers. Examples ofwireless systems include public land mobile networks (PLMN), satellitebased communication systems and different wireless local networks, forexample wireless local area networks (WLAN). Wireless systems can bedivided into coverage areas referred to as cells, such systems beingoften referred to as cellular systems. A cell can be provided by a basestation, there being various different types of base stations. Differenttypes of cells can provide different features. For example, cells canhave different shapes, sizes, functionalities and other characteristics.A cell is typically controlled by a control node.

A communication device is provided with an appropriate signal receivingand transmitting arrangement for enabling communications with otherparties. In wireless systems a communication device provides atransceiver station that can communicate with another communicationdevice such as e.g. a base station and/or another user equipment. Acommunication device such as a user equipment (UE) may access a carrierprovided by a base station, and transmit and/or receive on the carrier.

An example of cellular communication systems is an architecture that isbeing standardized by the 3rd Generation Partnership Project (3GPP). Arecent development in this field is often referred to as the long-termevolution (LTE) of the Universal Mobile Telecommunications System (UMTS)radio-access technology. In LTE base stations providing the cells arecommonly referred to as enhanced NodeBs (eNB). An eNB can providecoverage for an entire cell or similar radio service area.

Cells can provide different service areas. For example, some cells mayprovide wide coverage areas while some other cells provide smallercoverage areas. The smaller radio coverage areas can be located whollyor partially within a larger radio coverage area. For example, in LTE anode providing a relatively wide coverage area is referred to as a macroeNode B. Examples of nodes providing smaller cells, or local radioservice areas, include femto nodes such as Home eNBs (HeNB), pico nodessuch as pico eNodeBs (pico-eNB) and remote radio heads.

According to an aspect, there is provided a method comprising:determining in a base station of a first cell of a first network thatthere is an inactive second cell of a second, different network which isa candidate cell for a user equipment; and causing an activation messageto be sent to cause the activation of said inactive second cell.

The first cell may comprise a larger cell.

The second cell may comprise a smaller cell.

The determining may comprise determining from neighbour information thatthere is said inactive second cell.

The neighbour information may comprise previous information associatedwith said inactive second cell.

The neighbour information may comprise information about at least onecell of the first network and at least one cell of the second network.

The neighbour information may be provided in a neighbour relation table.

The method may comprise receiving first information from said userequipment.

The first information from said user equipment may comprise at least oneof operator information, network information, cell identity information,received signal strength information and reference signal receivedpower.

The activation message may comprise at least one wake up indicator, cellidentity information for said second cell, and frequency information.

The method may comprise receiving second information from said userequipment after said inactive second cell has been activated.

The second information may comprise information indicating if said userequipment is in a coverage area of said second cell.

The method may comprise determining if said user equipment is to beoffloaded to said second cell in dependence on said second informationfrom the user equipment after said second cell has been activated.

The method may comprise causing an offload message to be sent to causesaid user equipment to be offloaded, if said user equipment is to beoffloaded.

The offload message may comprise one or more of information identifyingthe operator, information identifying said smaller cell, informationidentifying said user equipment, traffic information and signal strengthinformation.

The causing a message to be sent may comprise causing said message to besent to a spectrum controlling entity of said first network.

The first network and said second network may be provided by differentnetwork operators.

According to another aspect, there is provided an apparatus in a basestation of a first cell in a first network, said apparatus comprising:means for determining that there is an inactive second cell of a second,different network which is a candidate cell for a user equipment; andmeans for causing an activation message to be sent to cause theactivation of said inactive second cell.

The first cell may comprise a larger cell.

The second cell may comprise a smaller cell.

The means for determining may determine from neighbour information thatthere is said inactive second cell.

The neighbour information may comprise previous information associatedwith said inactive second cell.

The neighbour information may comprise information about at least onecell of the first network and at least one cell of the second network.

The neighbour information may be provided in a neighbour relation table.

The apparatus may comprise means for receiving first information fromsaid user equipment.

The first information from said user equipment may comprise at least oneof operator information, network information, cell identity information,received signal strength information and reference signal receivedpower.

The activation message may comprise at least one wake up indicator, cellidentity information for said second cell, and frequency information.

The apparatus may comprise means for receiving second information fromsaid user equipment after said inactive second cell has been activated.

The second information may comprise information indicating if said userequipment is in a coverage area of said second cell.

The determining means may be for determining if said user equipment isto be offloaded to said second cell in dependence on said secondinformation from the user equipment after said second cell has beenactivated.

The apparatus may comprise causing means for causing an offload messageto be sent to cause said user equipment to be offloaded, if said userequipment is to be offloaded.

The offload message may comprise one or more of information identifyingthe operator, information identifying said smaller cell, informationidentifying said user equipment, traffic information and signal strengthinformation.

The causing means may be for causing a message to be sent may comprisecausing said message to be sent to a spectrum controlling entity of saidfirst network.

The first network and said second network may be provided by differentnetwork operators.

According to another aspect, there is provided an apparatus in a basestation of a first cell of a first network said apparatus comprising atleast one processor and at least one memory including computer code forone or more programs, the at least one memory and the computer codeconfigured, with the at least one processor, to cause the apparatus atleast to: determine that there is an inactive second cell of a second,different network which is a candidate cell for a user equipment; andcause an activation message to be sent to cause the activation of saidinactive second cell.

The first cell may comprise a larger cell.

The second cell may comprise a smaller cell.

The at least one memory and the computer code may be configured, withthe at least one processor, to determine from neighbour information thatthere is said inactive second cell.

The neighbour information may comprise previous information associatedwith said inactive second cell.

The neighbour information may comprise information about at least onecell of the first network and at least one cell of the second network.

The neighbour information may be provided in a neighbour relation table.

The at least one memory and the computer code may be configured, withthe at least one processor, to receive first information from said userequipment.

The first information from said user equipment may comprise at least oneof operator information, network information, cell identity information,received signal strength information and reference signal receivedpower.

The activation message may comprise at least one wake up indicator, cellidentity information for said second cell, and frequency information.

The at least one memory and the computer code may be configured, withthe at least one processor, to receive second information from said userequipment after said inactive second cell has been activated.

The second information may comprise information indicating if said userequipment is in a coverage area of said second cell.

The at least one memory and the computer code may be configured, withthe at least one processor, to determine if said user equipment is to beoffloaded to said second cell in dependence on said second informationfrom the user equipment after said second cell has been activated.

The at least one memory and the computer code may be configured, withthe at least one processor, to cause an offload message to be sent tocause said user equipment to be offloaded, if said user equipment is tobe offloaded.

The offload message may comprise one or more of information identifyingthe operator, information identifying said smaller cell, informationidentifying said user equipment, traffic information and signal strengthinformation.

The at least one memory and the computer code may be configured, withthe at least one processor, to cause said message to be sent to aspectrum controlling entity of said first network

The first network and said second network may be provided by differentnetwork operators.

According to another aspect, there is provided a method comprising:receiving a request in a second network from a first network, saidrequest requesting that a user equipment of said first network beoffloaded to a cell of said second network; and causing a response to beprovided to said request, said response being dependent on informationabout a resource which said first network is to provide to said secondnetwork.

According to another aspect, there is provided a method comprising:causing a request to be sent from a first network to a second network,said request requesting that a user equipment of said first network beoffloaded to a cell of said second network; and receiving a response tosaid request, said response being dependent on information about aresource which said first network is to provide to said second network.

The following may be used in conjunction with either of the aboveaspects.

The receiving and said causing may be repeated.

At least one of said request and response may comprise resourceinformation.

The resource may comprise one or more of spectrum of said first network,a financial reward, and a usage of at least a part of said firstnetwork.

The method may comprise determining candidate resource information

The resource may be dependent on or more of time of day, conditions inone or more of said first and second networks, and traffic information.

The first network and said second network may be provided by differentnetwork operators.

According to another aspect, there is provided an apparatus comprising:means for receiving a request in a second network from a first network,said request requesting that a user equipment of said first network beoffloaded to a cell of said second network; and means for causing aresponse to be provided to said request, said response being dependenton information about a resource which said first network is to provideto said second network.

According to another aspect, there is provided an apparatus comprising:means for causing a request to be sent from a first network to a secondnetwork, said request requesting that a user equipment of said firstnetwork be offloaded to a cell of said second network; and means forreceiving a response to said request, said response being dependent oninformation about a resource which said first network is to provide tosaid second network.

The following may be used in conjunction with either of the aboveaspects.

At least one of said request and response may comprise resourceinformation.

The resource may comprise one or more of spectrum of said first network,a financial reward, and a usage of at least a part of said firstnetwork.

The apparatus may comprise means for determining candidate resourceinformation

The resource may be dependent on or more of time of day, conditions inone or more of said first and second networks, and traffic information.

The first network and said second network may be provided by differentnetwork operators.

According to another aspect, there is provided an apparatus, saidapparatus comprising at least one processor and at least one memoryincluding computer code for one or more programs, the at least onememory and the computer code configured, with the at least oneprocessor, to cause the apparatus at least to: receive a request in asecond network from a first network, said request requesting that a userequipment of said first network be offloaded to a cell of said secondnetwork; and cause a response to be provided to said request, saidresponse being dependent on information about a resource which saidfirst network is to provide to said second network.

According to another aspect, there is provided an apparatus, saidapparatus comprising at least one processor and at least one memoryincluding computer code for one or more programs, the at least onememory and the computer code configured, with the at least oneprocessor, to cause the apparatus at least to: cause a request to besent from a first network to a second network, said request requestingthat a user equipment of said first network be offloaded to a cell ofsaid second network; and receive a response to said request, saidresponse being dependent on information about a resource which saidfirst network is to provide to said second network.

The following may be used in conjunction with either of the aboveaspects.

At least one of said request and response may comprise resourceinformation.

The resource may comprise one or more of spectrum of said first network,a financial reward, and a usage of at least a part of said firstnetwork.

The at least one memory and the computer code may be configured, withthe at least one processor, to determine candidate resource information

The resource may be dependent on or more of time of day, conditions inone or more of said first and second networks, and traffic information.

The first network and said second network may be provided by differentnetwork operators.

A computer program comprising program code means adapted to perform themethod(s) may also be provided. The computer program may be storedand/or otherwise embodied by means of a carrier medium.

In the above, many different embodiments have been described. It shouldbe appreciated that further embodiments may be provided by thecombination of any two or more of the embodiments described above.

Various other aspects and further embodiments are also described in thefollowing detailed description and in the attached claims.

Some embodiments will now be described, by way of example only, withrespect to the following Figures in which:

FIG. 1 shows a schematic diagram of a network according to someembodiments;

FIG. 2 shows a schematic diagram of a mobile communication deviceaccording to some embodiments;

FIG. 3 shows a schematic diagram of a control apparatus according tosome embodiments;

FIG. 4 shows examples of inter-operator service scenarios;

FIG. 5 shows a signal flow of offloading between two operators;

FIG. 6 shows an alternative negotiation process; and

FIG. 7 shows a second alternative negotiation process.

In the following certain exemplifying embodiments are explained withreference to a wireless or mobile communication system serving mobilecommunication devices. Before explaining in detail the exemplifyingembodiments, certain general principles of a wireless communicationsystem and nodes thereof and mobile communication devices are brieflyexplained with reference to FIGS. 1 to 3 to assist in understanding thecontext of the described examples.

A non-limiting example of the recent developments in communicationsystem architectures is the long-term evolution (LTE) of the UniversalMobile Telecommunications System (UMTS) that is being standardized bythe 3rd Generation Partnership Project (3GPP). The LTE employs a mobilearchitecture known as the Evolved Universal Terrestrial Radio AccessNetwork (E-UTRAN). Base stations of such systems are known as evolved orenhanced Node Bs (eNBs) and may provide E-UTRAN features such as userplane Radio Link Control/Medium Access Control/Physical layer protocol(RLC/MAC/PHY) and control plane Radio Resource Control (RRC) protocolterminations towards the communication devices. Other examples of radioaccess system include those provided by base stations of systems thatare based on technologies such as wireless local area network (WLAN)and/or WiMax (Worldwide Interoperability for Microwave Access). SomeWLANs are sometimes referred to by WiFi™, a trademark that is owned bythe Wi-Fi Alliance, a trade association promoting Wireless LANtechnology and certifying products conforming to certain standards ofinteroperability.

Different types of communication devices 101, 102, 103 can be providedwireless access via base stations or similar wireless transmitter and/orreceiver nodes providing radio service areas or cells. In FIG. 1different neighbouring and/or overlapping radio service areas or cells100, 110, 117 and 119 are shown being provided by base stations 106,107, 118 and 120. It is noted that the cell borders are schematicallyshown for illustration purposes only in FIG. 1. It shall be understoodthat the sizes and shapes of the cells or other radio service areas mayvary considerably from the omni-directional shapes of FIG. 1. A basestation site can provide one or more cells or sectors, each sectorproviding a cell or a subarea of a cell. Each communication device andbase station may have one or more radio channels open at the same timeand may send signals to and/or receive signals from more than onesource.

Base stations are typically controlled by at least one appropriatecontroller apparatus 108, 109 (for example as shown in FIG. 3) so as toenable operation thereof and management of mobile communication devicesin communication with the base stations. The control apparatus can beinterconnected with other control entities. The control apparatus cantypically be provided with memory capacity and at least one dataprocessor. The control apparatus and functions may be distributedbetween a plurality of control units. In some embodiments, each basestation can comprise a control apparatus. In alternative embodiments,two or more base stations may share a control apparatus. In someembodiments the control apparatus may be respectively provided in eachbase station.

Different types of possible cells include those known as macro cells,pico cells and femto cells. For example, transmission/reception pointsor base stations can comprise wide area network nodes such as a macroeNode B (eNB) which may, for example, provide coverage for an entirecell or similar radio service area. A base station can also be providedby small or local radio service area network node, for example Home eNBs(HeNB), pico eNodeBs (pico-eNB), or femto nodes. Some applicationsutilise radio remote heads (RRH) that are connected to for example aneNB. As cells can overlap a communication device in an area can listenand transmit to more than one base station. Smaller radio service areascan be located entirely or at least partially within a larger radioservice area. A communication device may thus communicate with more thanone cell.

In a particular example, FIG. 1 depicts a larger cell 100. In thisexample the larger cell 100 can be provided by a wide area base station106 provided by a macro-eNB. The larger cell may be a macro cell. Themacro-eNB 106 transmits and receives data over the entire coverage ofthe cell 100. A smaller cell 110 in this example is a pico-cell. Asmaller cell can also be provided by another suitable small area networknode 118 such as Home eNBs (HeNB) (femto cell) or another pico eNodeBs(pico-eNB). A yet further cell 119 is shown to be provided by a remoteradio head (RRH) 120 connected to the base station apparatus of cell100. These smaller cells may be referred to as small cells in thedocument.

Base stations may communicate via each other via fixed line connectionand/or air interface. The logical connection between the base stationnodes can be provided for example by an X2 interface. In FIG. 1 thisinterface is shown by the dashed line denoted by 105.

The base stations may communicate via one or more entities 111 and 112with a core network 113. These one or more entities and/or one or moreentities in the core network may have a spectrum control function.

One or more entities may provide a spectrum control function solely orin addition to one or more other functions. A spectrum controller may beresponsible for controlling the shared spectrum resources in theinter-operator situations.

The spectrum controller may be part of the O&M (operation andmaintenance) system and/or part may be distributed within a network(e.g. in a base station). This may depend on how dynamic the spectrumcontrol is. For example at a higher network level shared spectrum bandsare determined with constraints (for example location, time, and/orpower) and at a lower level the decisions could be made how to use theshared resources based on the local conditions. The lower level can bein a base station or a radio network controller. The higher level can bein the core network.

A possible mobile communication device for transmitting to and receivingfrom a plurality of base stations will now be described in more detailwith reference to FIG. 2 showing a schematic, partially sectioned viewof a mobile communication device 200. Such a device is often referred toas user equipment (UE) or terminal. An appropriate mobile communicationdevice or user equipment may be provided by any device capable ofsending radio signals to and/or receiving radio signals from multiplecells. Non-limiting examples include a mobile station (MS) such as amobile phone or what is known as a ‘smart phone’, a portable computerprovided with a wireless interface card, and USB stick or ‘dongle’ withradio, or other wireless interface facility, personal data assistant(PDA) provided with wireless communication capabilities, or anycombinations of these or the like. A mobile communication device mayprovide, for example, communication of data for carrying communicationssuch as voice, electronic mail (email), text message, multimedia and soon. It should be appreciated that in some embodiments, the userequipment may be provided at a generally fixed location. The mobiledevice may receive and transmit signals over an air interface 207 withone, two or more base stations via an appropriate transceiver apparatus.In FIG. 2 transceiver apparatus is designated schematically by block206. The transceiver apparatus 206 may be provided for example by meansof a radio part and associated antenna arrangement. The radio part isarranged to communicate simultaneously with different stations. Theradio part may also be arranged to communicate via different radiotechnologies. For example, the radio part can provide a plurality ofdifferent radios. The antenna arrangement may be arranged internally orexternally to the mobile device.

A mobile communication device is also provided with at least one dataprocessing entity 201, at least one memory 202 and other possiblecomponents 203 for use in software and hardware aided execution of tasksit is designed to perform, including control of access to andcommunications with access systems and other communication devices. Thedata processing, storage and other relevant control apparatus can beprovided on an appropriate circuit board and/or in chipsets. Thisfeature is denoted by reference 204.

The user may control the operation of the mobile device by means of asuitable user interface such as key pad 205, voice commands, touchsensitive screen or pad, combinations thereof or the like. A display208, a speaker and a microphone can also be provided. Furthermore, amobile communication device may comprise appropriate connectors (eitherwired or wireless) to other devices and/or for connecting externalaccessories, for example hands-free equipment, thereto.

FIG. 3 shows an example of a control apparatus for a communicationsystem. In some embodiments a base station can comprise a controlapparatus such as shown in FIG. 3. This control apparatus may beprovided in a spectrum control entity 33. The control apparatus 300 canbe configured to provide control functions by means of the dataprocessing facility in accordance with certain embodiments describedbelow. For this purpose the control apparatus comprises at least onememory 301, at least one data processing unit 302, 303 and aninput/output interface 304. Via the interface the control apparatus canbe coupled to a receiver and a transmitter of the base station where theapparatus is provided in the base station. The control apparatus can beconfigured to execute an appropriate software code to provide thecontrol functions.

Some embodiments relates to mobile wireless communication systems, suchas 3GPP Long-Term Evolution Advanced (LTE-A).

Some embodiments may provide inter-operator spectrum sharing tofacilitate Flexible Spectrum Utilization (FSU).

As discussed above a small cell can be deployed with the macro celllayer. Offloading of a UE, which is attached to a macro cell, to a smallcell may improve the spectrum efficiency, enlarge the coverage and/orsave the energy of a UE. The shortage of spectrum makes small cell FSU auseful tool. On the one hand, with increasing of small cell deploymentdensity, the available spectrum may be scarce. On the other hand, if afixed part of the spectrum is used by only one operator, some spectrumwill be wasted when there is no traffic. Inter-operator spectrum sharingmay be one way of improving the spectrum efficiency, for example forsmall cells.

In some embodiments, it may be useful to ensure that where possible, aUE is served by a small cell as far as possible. However, in some cases,there may be no suitable intra-operator small cell to serve a UE. Inthis situation, some embodiments may find an inter-operator small cell(i.e. a cell belonging to a different operator) and make this cell servethe UE. There may be some reward for the different operator. In someembodiments, the operators may be competitors and each operator may wantto maximize their own interest. In some embodiments, reward strategiesmay be considered in the inter-operator offloading mechanism. This mayimprove the utilization rate of the vacant spectrum.

By way of example only and with reference to FIG. 4, some examples ofsome possible cases where a UE associated with a macro cell can beserved by an inter-operator small cell.

FIG. 4 shows a scenario where three examples, case 1, case 2 and case 3where user equipment is initially communicating with the macro cell basestation 10. FIG. 4 also shows the situation subsequently where the userequipment is associated with a small cell.

In the system shown in FIG. 4, a macro cell 26 is served by the basestation 10 which is associated with a first operator.

In the first case, a first small cell 32 is shown which is associatedwith the first operator whilst a second small cell 28 is associated witha second operator. Cell 32 is served by a small cell base station 18 ofthe first operator whilst the cell 28 is served by base station 16 ofthe second operator. In the situation of the first case, the userequipment 17 is in a small cell of the second network operator but not asmall cell belonging to the first network operator. In the situation ofcase 1, the user equipment 17 is attached to the base station 16 of thesecond operator. However, the respective cell of the second operator mayhave to be woken up or activated.

In the example of case 2, a user equipment 12 is again in communicationwith the macro cell base station 10. The user equipment 12 is in an areaof overlap between a small cell 36 of the first operator and a smallcell 34 of the second operator. The cell 36 of the first operator isserved by a small cell base station 24 whilst the cell 34 is served bythe small cell base station 22 of the second operator. In this scenarioof case 2, the traffic load of the base station 24 associated with thefirst operator is too high to serve the user equipment and there are noother small cells of the first operator around the user equipment 12.However, there is a small cell 34 of the second operator which canprovide service to the user equipment. Accordingly, in this example, theuser equipment is then served by the small cell base station 22 of thesecond operator. The cell of the second operator may be sleeping orinactive and may need to be activated in order for the user equipment tocommunicate with the base station of that small cell.

Reference is now made to the third scenario. In this case, the userequipment 14 is again arranged in a region of overlap of a small cell 30which is served by a base station 20 of the first operator and a smallcell 32 which is served by a base station 33 of the second operator. Inthe third case, for some reason, the user equipment is not properlyserved by the base station 20 of the first operator. This may be if theuser equipment is at the edge of the small cell or if there areobstacles between the user equipment and the small cell such that thereceived signal is too low to serve this user equipment. Again, there isno other small cell of the first operator around the user equipment.However, this user equipment is also in the small cell of the secondoperator. Again, in this example, the cell 32 may be sleeping orinactive and may be made active or woken up such that the cell 32 of thesecond operator can serve the user equipment.

In the above examples, the small cell of the second operator may beactive or inactive or sleeping. If the small cell is inactive orsleeping, that cell will need to be activated. For simplicity, two smallcells are shown for each case but in some embodiments, the situation maybe more complex and have more than two cells in each scenario.

Spectrum sharing has been proposed to exploit spectrum efficiency infuture communication system. Typically proposals focus on intra-operatorsystems. There may be a primary system and one or more secondary systemsin the spectrum sharing system model. In this situation, when afrequency is needed by the primary system, the secondary system mayconcede.

In some situations such as co-primary inter-operator spectrum sharing,all the operators may have equal rights for the co-shared spectrum.

Offloading of users from a macro cell layer to a small cell layer wherethe macro layer and small cell layer are on different carrierfrequencies is one deployment scenario. As an energy efficient method, asleeping mechanism may have some advantages although the small celldiscovery process may be more complex.

Some embodiments may provide an inter-operator service mechanism. Thismay allow the spectrum be used more efficiently. Some embodiments mayprovide an inter-operator small cell wake up mechanism and/or anegotiation process.

Some embodiments may provide sleeping inter-operator small celldiscovery methods. A sleeping inter-operator small cell discovery methodof some embodiments may use the historical information of neighbourrelationship. In some embodiments a neighbour relation table will alsoinclude the neighbours of inter-operators as well as intra-operatorcells. In some embodiments, a separate table may be provided forinter-operator cells and a separate table for intra-operator cells. Asmall cell of a second operator once active will be stored in theneighbour table of a small cell of a first operator, assuming the twocells are neighbours. In some embodiments this will be stored in a tablesuch as a neighbour relation table (NRT).

In one example a UE is in the small cell of a first operator and that UEhas stored the historical information of neighbour relationship,including information about neighbouring cells of a second operator. TheUE then may use the historical neighbour relation table of the smallcell of the first operator to discover the small cell of the secondoperator.

When the UE of the first operator tries to access the small cell of thesecond operator and that cell of the second operator is sleeping, thefirst operator may send an inter-operator wake up indication message tothe second operator. The first operator informs or requests the secondoperator to wake up the small cell of the second operator. The firstoperator may provide the second operator with a carrier frequency f₀which is to be used by the small cell of the second operator. Thisinter-operator wake up indication message may comprise one or more ofthe following parameters:

-   -   A wake up indicator which indicates that the target sleeping        small cell should wake up.    -   The target cell ID that indicates which small cell is to be        activated be activated.    -   A carrier frequency f₀ which is provided by operator A to the        target cell ID.

Once a RSRP (Received signal received power) is higher than a threshold,the first operator may attempt to offload its UE (which may be attachedto a macro cell of the first operator or to a small cell of the firstoperator which is perhaps unable to service the UE adequately) to thesmall cell of operator B.

The first operator may send an inter-operator service message to itsservice management entity which may comprise one or more of thefollowing parameters:

-   -   An operator flag that indicates the operator to which the target        small cell belongs.    -   The target cell ID that indicates the small cell to which the UE        will be offloaded.    -   RSRP from the target cell to the UE.        -   International Mobile Station Identify (IMSI) of the UE.        -   Traffic type and/or QoS (quality of service) such as FTP,            VoIP (voice over internet protocol), video, etc.

Any suitable negation process may be used in embodiments. In a firstexample, when the service management entity of the first operator hasreceived the inter-operator service message, it may send aninter-operator offloading request message to a corresponding entity orany other suitable entity of the second operator. This inter-operatorservice request message may comprise one or more of the followingparameters:

-   -   The target cell ID of the small cell to which the UE is to be        offloaded.        -   The IMSI of the UE.    -   RSRP from the target cell to UE.    -   Traffic type and/or QoS (quality of service) such as FTP (file        transfer protocol), VoIP (voice over internet protocol), video,        or the like.

Once the second operator has received the inter-operator service requestmessage from the first operator, the second operator will calculate theneeded resource based on the message. The second operator may send aninter-operator reward request message to the first operator. This maycomprise information about the reward for the second operator and may bedependent on the required resource. The inter-operator reward requestmessage may comprise:

The reward for second operator claimed by the second operator. Thereward may be one or more of spectrum, real currency, and any othersuitable resource. Other reward options may comprise a predefined valueof the exchanged spectrum or other resources, and/or usage of the otheroperator network structure. The predefined value may be negotiatedbeforehand with operators. In some embodiments there may be a predefinedabstraction or mapping of the value to the exchanged resources.

In another example, when the service management entity of first operatorhas received the inter-operator service message, the service managemententity may send an inter-operator service request message to acorresponding entity of the second operator. This inter-operator servicerequest message may comprise one or more of the following parameters:

-   -   The target cell ID of the small cell to which the UE is to be        offloaded.    -   IMSI of the UE.    -   RSRP from the target cell to the UE.    -   Traffic type and/or QoS (quality of service) such as FTP, VoIP        (voice over internet protocol), video, etc.    -   The reward for the second operator which is offered by the first        operator. The reward for second operator claimed by the second        operator. The reward may be one or more of the previously        described options.

FIG. 5 shows one example of signaling which may be used in someembodiments. In the example shown in FIG. 5 only one small cell for eachof two operators is shown for convenience of description. In someembodiments, there may more than two small cells associated with theoperators.

As shown in step S1, the UE (UE_(A)) is communicating with its macrocell (MeNB_(A)) of the first operator.

The UE may be in an area covered by one or more small cells. The smallcells may be of its own operator and/or a second different operator.

In step S2, the UE will scan the spectrum pool. The small cells ofdifferent operators may exchange neighbour list tables between eachother so each small cell base station will know the neighbours of itsown network and also neighbours of the other operator's network. Basedon the neighbour list information, the UE may scan the componentcarriers of the spectrum pool and determine the missing neighbour whichshould be there.

In step S3, the UE reports the measurement result to its macro cell basestation MeNB_(A). The measurement report may comprise one or more of: anOP (operator) flag, cell ID and RSRP.

In one example, there is no small cell of the first operator suitablefor the UE and there is no active small cell of the second operatorsuitable for the UE. In step S4, the base station MeNB_(A) determines ifthere are any sleeping small cells SeNB_(B) of the second operator. Thebase station will use the neighbor history information.

In step S5, the macro cell base station MeNB_(A) of the first operatorcauses a wake up indication message to be sent to the sleeping smallcell SeNB_(B) of the second operator. This message may be sent via aspectrum control (SC) entity of the first operator, a spectrum controlentity of the second operator and a macro cell base station MeNB_(B)associated with the sleeping small cell of the second network operator.This will wake up or activate the sleeping small cell of the secondoperator. The wake up indication message may comprise one or more of awake up indicator, target cell ID, and working frequency.

In step S6, the UE scans the frequency f₀ to determine if the UE is incoverage area of the small cell of the second operator.

In step S7, the UE reports the measurement result to macro cell basestation MeNB_(A) of the first operator.

In step S8, the macro cell base station MeNB_(A) of the first operatordetermines if it is necessary to offload this UE to the small cell ofsecond operator B. If it is determined that the UE is to be offloaded tothe small cell of the second operator, the next step is step S9.Otherwise, the UE MUE_(A) will continue to communicate with macro cellbase station MeNB_(A) of the first operator (S1). In some embodiments,only when there is a small cell of the second operator and the RSRP ishigher than a threshold, will the offload will be triggered. Of courseany other suitable mechanism may alternatively or additionally be usedto determine if a UE is be offloaded to a small cell base station of adifferent operator.

In step S9, the macro cell base station of the macro cell base stationMeNB_(A) sends an inter-operator service message to the spectrum controlentity of the first operator. This message may be an offloading message.The offloading message may comprise one or more of an operator flagidentifying the operator, target cell ID, RSRP, IMSI, and traffic type.

In step S10, there is a negotiation process between the spectrum controlentity of the first operator and the spectrum control entity of thesecond operator. This will be discussed in more detail later.

In step S11, the spectrum control entity SC_(A) of the first operatorcauses a message to be sent to the UE via the macro cell of the firstbase station and the base station of the first cell SeNB_(A) that the UEwill be handed over to small cell SeNB_(B) of the second operator. Thismay indicate that the small cell base station of the first operatorneeds to make some preparation for the handoff. This assumes in thisexample that UE is in communication with the small cell of the firstoperator. In some embodiments, the message may be provided directly bythe macro cell base station The inter-operator handover informingmessage may comprise one or more of the target cell ID of small cellSeNB_(B) of the second operator and the working frequency.

In step S12, the spectrum control entity of the second operator causes amessage to be sent to the small cell of the second operator via themacro cell base station of the second operator associated with the smallcell. This message advises the small cell base station that the UE willaccess that cell. That cell will prepare for the offload of that UE tothat small cell of the second operator. The inter-operator serviceinforming message may comprise one or more of the IMSI of UE and theworking frequency.

It should be appreciated that steps S11 and S12 can take place in eitherorder or at the same time.

In step S13, the UE sends a connection request to the small cell basestation of the second operator. That base station will send anacknowledgement to the UE.

In step S14, the UE is attached to the small cell base station of thesecond operator.

Two different negotiation processes between two operators will now bedescribed.

Reference is made to FIG. 6 which shows a first flow.

In step T1, the spectrum controller of the first operator sends aninter-operator service request to the spectrum controller of the secondoperator. This message may comprise one or more of the target cell ID,IMSI, RSRP, and traffic type.

In step T2, the spectrum controller of the second operator calculatesthe reward. The reward may be calculated or determined in any suitableway. For example, the reward may be determined according to one or bothof the RSRP and the user's traffic type. For example, assume the RSRP isP and the data rate restriction for the traffic type is not lower thanR₀. If the reward is spectrum, then the required reward spectrum may beR₀/log₂(1+P/N₀) according to the Shannon formulation. It should beappreciated that the reward can take any suitable form and the rewardmay be calculated using any suitable method.

In step T3, the spectrum controller of the second operator sends aninter-operator reward request message to spectrum controller of thefirst operator. The spectrum reward desired may be indicated in theinter-operator request message. Alternatively, in some embodiments, therequest may indicate merely that a reward is required. If the reward isspectrum, the spectrum SC_(B) required by the second operator from thefirst operator may be the same or higher than the needed spectrum forUE. The second operator can use the spectrum to serve its own users aswell as the UE of the first operator.

In step T4, the spectrum controller of the first operator sends aninter-operator reward response message to the spectrum controller of thesecond operator.

This step and step T3 may repeat until the two operators agree with thereward, in some embodiments. In other embodiments the two operators mayhave already agreed a suitable reward. The reward may be dependent onthe conditions of one or other of the networks.

Reference is made to FIG. 7 which shows an alternative negotiationprocess of some embodiments.

In step A1, the spectrum controller of the first operator calculates ordetermines the reward in any suitable way such as described in relationto the previous embodiment. For example the reward may be determined independence on one or more of the RSRP and the traffic type of the userequipment.

In step A2, the spectrum controller of first operator sends aninter-operator service request message to the spectrum controller of thesecond operator. This message may comprise one or more of the targetcell ID, IMSI, RSRP, traffic type, and the reward.

In step A3, the spectrum controller of the second operator sends aninter-operator service response message to spectrum controller A.

This step and step A1 may repeat until the two operators agree a reward.

For different cases, the reward strategy may be different. Some exampleswill now be discussed in relation to the scenarios shows in FIG. 4.

For case 1, there is no small cell belonging to the first operatoraround the UE. The first operator may provide to the second operatorsome spectrum from one or more small cells away from the UE as thereward.

For case 2, the traffic load of the base station of the small cell ofthe first operator is high. The spectrum is thus constrained, so thefirst operator may take some spectrum from one or more other small cellsaway from the UE to provide as a reward to the second operator.

For case 3, the traffic load of the small cell SeNB_(A) of the firstoperator may be low, and the first operator will provide some spectrumof the small cell SeNB_(A) of the first operator as the reward tooperator B.

The rewards may be dependent on the traffic load on the networks. Forexample, at a busy time, the second operator will agree to serve the UEin return for a higher reward. However, at a less busy time, the secondoperator will provide a lower reward to the second operator

In some embodiments, the reward may be dependent on the type of trafficand/or the QoS.

In some embodiments, each operator may have one or more thresholds whichmay be dependent on one or more conditions. Those conditions maycomprise one or more of network load, cell load, traffic type, trafficvolume, quality of service and/or any other suitable condition. One ormore thresholds may be used to determine whether an operator is toprovide spectrum to another operator. One or more thresholds may be usedto determine if a network operator is willing to provide the requestedreward.

It should be appreciated that in some embodiments, allocation ofspectrum and/or other reward may be agreed by the operators in advance.The reward may be determined by taking into account one or moreconditions such as time of day, type of traffic, load or the like.

The above embodiments have used spectrum as a reward. It should beappreciated that the reward may alternatively or additionally take anyother suitable form. The type of reward provided may be dependent on oneor more conditions. These conditions may be as discussed above.

Some embodiments may have one or more of the following advantages:

-   -   The negotiation process may result in a better use of the        spectrum e.    -   A UE may be served with small cells as far as possible.    -   Some embodiments may improve the probability of a UE accessing        small cells, and this may be energy efficient from the UE        aspect. This is because the UE can use lower power        transmissions.    -   Even if there is no serving cell for a UE available from its own        operator, a different operator may be able to provide a cell for        this UE. This may improve the user experience.

In the above reference is made to small cells. It should be appreciatedthat other embodiments may alternatively or additionally be used withother sizes of cell.

Some communications have been described as being via macro cells. Itshould be appreciated that in other embodiments, different communicationpaths may be provided to for example activate a sleeping cell.

In the above reference is made to inter operator situations. It shouldbe appreciated that in other embodiments, there may be two separatenetworks. Those networks may be operated by the same operator.

A small cell is generally a cell which is smaller than for example alarger cell. The larger cell may be a macro cell. The smaller cell maybe a pico cell, a femto cell, a home NB cell and/or any other suitablesmaller cell.

An appropriately adapted computer program code product or products maybe used for implementing the embodiments, when loaded on an appropriatedata processing apparatus, for example for control operations. Theprogram code product for providing the operation may be stored on,provided and embodied by means of an appropriate carrier medium. Anappropriate computer program can be embodied on a computer readablerecord medium. A possibility is to download the program code product viaa data network. In general, the various embodiments may be implementedin hardware or special purpose circuits, software, logic or anycombination thereof. Embodiments may thus be practiced in variouscomponents such as integrated circuit modules. The design of integratedcircuits is by and large a highly automated process. Complex andpowerful software tools are available for converting a logic leveldesign into a semiconductor circuit design ready to be etched and formedon a semiconductor substrate.

It is also noted herein that while the above describes exemplifyingembodiments of the invention, there are several variations andmodifications which may be made to the disclosed solution withoutdeparting from the scope of the present invention.

1-30. (canceled)
 31. A method comprising: determining in a base stationof a first cell of a first network that there is an inactive second cellof a second, different network which is a candidate cell for a userequipment; and causing an activation message to be sent to cause theactivation of said inactive second cell.
 32. A method as claimed inclaim 31, wherein at least one of said first cell comprises a largercell and said second cell comprises a smaller cell.
 33. A method asclaimed in claim 31, comprising receiving first information from saiduser equipment, wherein said first information from said user equipmentcomprises at least one of operator information, network information,cell identity information, received signal strength information andreference signal received power.
 34. A method as claimed in claim 31,wherein said activation message comprises at least one of a wake upindicator, cell identity information for said second cell, and frequencyinformation.
 35. A method as claimed in claim 31, comprising receivingsecond information from said user equipment after said inactive secondcell has been activated, wherein said second information comprisesinformation indicating if said user equipment is in a coverage area ofsaid second cell.
 36. A method as claimed in claim 35, comprisingdetermining if said user equipment is to be offloaded to said secondcell in dependence on said second information from the user equipmentafter said second cell has be activated.
 37. A method as claimed inclaim 36, comprising causing an offload message to be sent to cause saiduser equipment to be offloaded, if said user equipment is to beoffloaded.
 38. A method as claimed in claim 37, wherein said offloadmessage comprises one or more of information identifying the operator,information identifying said second cell, information identifying saiduser equipment, traffic information and signal strength information. 39.An apparatus in a base station of a first cell of a first network saidapparatus comprising at least one processor and at least one memoryincluding computer code for one or more programs, the at least onememory and the computer code configured, with the at least oneprocessor, to cause the apparatus at least to: determine that there isan inactive second cell of a second, different network which is acandidate cell for a user equipment; and cause an activation message tobe sent to cause the activation of said inactive second cell.
 40. Anapparatus as claimed in claim 39, wherein the at least one memory andthe computer code are configured, with the at least one processor, toreceive at least one of first information from said user equipment andsecond information from said user equipment after said inactive secondcell has been activated.
 41. An apparatus as claimed in claim 40,wherein the first information from said user equipment comprises atleast one of operator information, network information, cell identityinformation, received signal strength information and reference signalreceived power.
 42. An apparatus as claimed in claim 40, wherein thesecond information comprises information indicating if said userequipment is in a coverage area of said second cell.
 43. An apparatus asclaimed in claim 39, wherein the activation message comprises at leastone wake up indicator, cell identity information for said second cell,and frequency information.
 44. An apparatus as claimed in claim 39,wherein the at least one memory and the computer code are configured,with the at least one processor, to cause an offload message to be sentto cause said user equipment to be offloaded, if said user equipment isto be offloaded.
 45. An apparatus as claimed in claim 44, wherein theoffload message comprises one or more of information identifying theoperator, information identifying said second cell, informationidentifying said user equipment, traffic information and signal strengthinformation.
 46. An apparatus comprising at least one processor and atleast one memory including computer code for one or more programs, theat least one memory and the computer code configured, with the at leastone processor, to cause the apparatus at least to: receive a request ina second network from a first network, said request requesting that auser equipment of said first network be offloaded to a cell of saidsecond network; and cause a response to be provided to said request,said response being dependent on information about a resource which saidfirst network is to provide to said second network.
 47. An apparatus asclaimed in claim 46, wherein said at least one of said request andresponse comprises resource information.
 48. An apparatus as claimed inclaim 46, wherein said resource comprises one or more of spectrum ofsaid first network, a financial reward, and an usage of at least a partof said first network.
 49. An apparatus as claimed in claim 46, whereinthe at least one memory and the computer code are configured, with theat least one processor, to determine candidate resource information inthe response to be transmitted to the first network.
 50. An apparatus asclaimed in claim 46, wherein said resource is dependent on or more oftime of day, conditions in one or more of said first network, andtraffic information.